Deep Sea Seal

[SteveIOW]

I need to slide my Yanmar 2GM20 forward into the cabin to renew the 4 engine mounts (Engine bay space far too tight to undertake this in situ). I intend to do this afloat at my mooring. I have a jig to maintain shaft alignment when the gearbox coupling is unbolted but this jig does not prevent shaft sliding forward and taking all the compression off the Deep Sea shaft face seal. I could prevent water ingress by tightening the thumb screw jubilee clip provided on the non-rotating portion of the Deep Sea seal. (This jubilee clip is intended for emergency use only in the event of a seal failure. It clamps the fixed portion onto the shaft. The shaft cannot be rotated once clip is tightened but that's better than sinking). Once I've got the engine is back where it belongs on its new mounts and the shaft coupling re-connected I would then undo this "emergency shaft clamp" and be back where I started. HOWEVER the booklet that came with the Deap Sea Seal states that once the emergency clamp has been used a complete new Deep Sea Seal should be fitted. WHY? The seal is only two seasons old and little used. I can't see what damage can be done to the seal by merely squeezing the rubber onto the the shaft and then releasing it a couple of days later. DO YOU AGREE?

(It's not the cost of replacing the Deep Sea Seal again. It's the fact that I would have to bring the boat ashore to do it.)

 

[Simondjuk]

I don't know about the Deep Sea, but a PSS seal will remain watertight with barely any pressure between rotor and carbon cuff. I'd have thought there's enough drag in the cutlass bearing to prevent the shaft sliding so freely that the seal won't hold water.

Alternatively, slide the rotor back along the shaft to keep it in contact with the cuff whilst you draw the shaft forward until the prop/anode/rope cutter is against the shaft log. Then compress the seal a little and nip the rotor up. Voila, one seal compressed on a shaft which is securely fixed in a temporary position.

Tightening the clip may do no harm, but why risk it if either of the above negate the need?

 

[Tranona]

You should be able to slide the seal bellows back and reclamp to keep the two faces together. However your problem is just illustrating the weakness of that particular design and long term you may want to consider replacing it with something more robust.

 

[30boat]

I used to have a Deep Sea Seal .It doesn't take a lot of pressure to make them watertight.I did remove the engine several times with the boat afloat without water rushing in.I would rig a line betwen the shaft flange and a screw or something to pull it back.
When I got fed up with the ineficiency of the seal I switched to a Volvo seal and this whole thing was no more an issue.